Transitional elements for the transfer of dispersions during processing in a rotor-stator dispersion machine

ABSTRACT

To avoid even in rotor-stator dispersion machines with high suction power that the drawn liquid is set into a rotational movement whereby the dispersion performance is impaired, the invention provides transitional elements, such as an intermediate piece, for establishing the connection between a rotor-stator dispersion machine and a container. The rotor-stator dispersion machine comprises a rotor-stator system having at least one toothed ring. The container has a longitudinal axis and an outlet. The intermediate piece has a first opening for the connection with the outlet of the container and a second opening for the connection with the rotor-stator dispersion machine. The intermediate piece comprises a tube line that extends between the first and the second opening and has at least in some sections a longitudinal axis that is inclined relative to the longitudinal axis of the container by an angle α 30  in the range of 0° to 90°.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of and claims priority to U.S. patentapplication Ser. No. 13/062,296 with a 371 entry date of Mar. 4, 2011,which in turn claims priority to International Application Serial NumberPCT/EP2009/006377 filed on Sep. 3, 2009, and German Application NumberDE 10 2008 045 820.1 filed on Sep. 5, 2008. Furthermore, U.S. patentapplication Ser. No. 13/062,296 is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates generally to transitional elements for thetransfer of dispersions during processing in an installation system witha rotor-stator dispersion machine. Specifically, the invention providesan intermediate piece for connecting a rotor-stator dispersion machinewith a container, an outlet means for connecting the rotor-statordispersion machine with a discharge apparatus, in particular a tubeline, and an inlet pipe for adding a fluid to the container.

BACKGROUND OF THE INVENTION

In process engineering the general practice for the preparation ofproducts involves working with ratios of quantities as set forth in arecipe. Some raw materials are added in gram-range quantities, others inlarge quantities. In addition, some raw materials require high shearrates when being added, others low shear rates. When producingdispersions, in particular when producing emulsions, in order to achievea final product with the desired properties in terms of the sizedistribution of the disperse phase, flow properties and stability of theproduct relative to thermal and mechanical stresses as well as changesover time, it is extremely important that the necessary steps for addingthe inner phase in the outer phase are defined and reliably implementedin terms of the process technology both during the dispersion as well asthe stabilization of the obtained product. Dispersions, in particularemulsions, are produced industrially by various processes. The selectedprocess depends on the type of the dispersion as well as on the finenessof the dispersed or particulate phase that is suitable for achieving astable dispersion over the required time period. A stable dispersion isdefined as a material system having a particle size distribution of thedispersed phase and/or flow properties, in particular, the viscosity ofwhich does not change substantially over the prescribed time period.

Partial over-concentration is often encountered especially in emulsionsand suspensions with a high disperse-phase portion; i.e., localizedand/or temporal deviations regarding particle density in the surroundingfluid. According to conventional methods, such over-concentrations canonly be homogenized by operation with extended mixing and dispersiontimes. The risk for the occurrence of over-concentrations is intensifiedfor containers with low filling levels because the commonly used devicesset the liquid that is inside the container into a rotating motion. Thiscauses a reduction of the actual energy quota that is introduced intothe fluid. Said effect is especially pronounced under vacuum conditionswhen the drawing-in of the fluid from the container is disrupted.

Consequently, it is necessary to maintain a certain minimum fillinglevel inside the container in order to be able to feed the premix withthe desired defined properties to the rotor-stator dispersion machineand to prevent, in particular, any aspiration of air into therotor-stator system. To achieve full dispersion power this minimum batchvolume is approximately 35% of the maximum filling level of thecontainer for the current rotor-stator dispersion machines that arecommercially available. Only if these conditions are met, will there nolonger be any detectable differences in the droplet-size distributionsbetween partial and full batches.

The usual rotor-stator dispersion machines therefore come with thedisadvantage of having a relatively high minimum filling level. This iswhy the possibilities for varying batch quantities that are to beprocessed by a machine, so-called batch size ranges, are very limited.In addition, the minimum filling level must also be maintained whenrunning the cleaning applications of the machines; thus, largequantities of cleaning agent are needed. This means a relatively largequantity of fluid is always being moved around inside the respectiveinstallation and the total power that is introduced in the fluid isdissipated inside this large volume, whereby the achieved energy densityinside the product is relatively small. This can result in inefficientconditions for the dispersing action. Moreover, there is a risk that theparticles and/or the drops of an emulsion coalesce.

SUMMARY OF THE INVENTION

Therefore, one of the objects of the present inventions consists inproviding larger flexibility in terms of the batch size ranges, whichmeans to provide for a possibility of providing a larger band in whichminimum to maximum size batches can be satisfactorily processed. Inaddition, another objective of the present invention envisions achievingan enhanced energy application inside the product by improving theutilization of the applied power, thereby allowing for an efficientbreak-down of drops. Moreover, another objective of the inventionenvisions preventing, in as much as possible, the coalescing of dropsand/or aggregation of particles when they leave the rotor-statordispersion machine. In addition, the invention envisions providing forfaster batch times, which means fewer runs and, consequently, fastertimes for achieving the completion of the dispersion task.

The invention provides an intermediate piece for the connection of arotor-stator dispersion machine with a container. The rotor-statordispersion machine comprises a rotor-stator system having at least onetoothed ring. The container has a longitudinal axis and an outlet. Theintermediate piece comprises a first opening for establishing theconnection with the outlet of the container and a second opening forestablishing the connection with the rotor-stator dispersion machine.The intermediate piece comprises a tube line extending between the firstand second openings and having at least in some sections a longitudinalaxis that is inclined by an angle α₃₀ (alpha_30) in the range of 0° to90° relative to the longitudinal axis of the container.

The inventor realized that especially rotor-stator dispersion machineswith high suction power tend to set the suctioned fluid into a rotatingmotion, which in turn reduces the dispersing power. In emulsions thisresults in a broad range of drop-size distributions and/or larger meandrop-size diameters. Moreover, eddies may form inside the container andair may be drawn into the product. If the rotor-stator system hashigh-performance suction, an auxiliary conveying means is frequentlynecessary, such as a propeller agitator, in order to feed sufficientproduct into the rotor-stator system. But the rotation of the productbefore it flows into the rotor-stator system also occurs and/or is evenpromoted by the auxiliary conveying means in the form of a propeller.

Since the invention causes, due to the inclined intermediate piece, adisruption of the rotation of the fluid before the feed stream entersthe rotor-stator dispersion machine, these problems are avoided. Theinvention thus achieves the objectives as set forth above and helps toovercome the disadvantages of conventional rotor-stator systems. Theintermediate piece determines the installation angle for the connectionof the dispersion machine and the container. By reducing the rotationalmovement of the product it is possible to achieve minimum batch sizes of10% of the maximum container content.

An advantageous improvement envisions an angle α₃₀ between thelongitudinal axis of the tube line and the longitudinal axis of thecontainer. In this context, the intermediate piece is envisioned toestablish the connection of a rotor-stator dispersion machine with acontainer having a container floor that tapers toward the outlet at anangle α_(Konus) (alpha_konus). Thus, the value for angle α₃₀ isessentially one half of α_(Konus). This way, it is possible for the feedstream of the product to be added over a sufficiently large area fromthe container, and essentially directly over the tapered containerfloor, to the dispersion machine.

In a further embodied example of the intermediate piece according theinvention the tube line comprises at least one area where the wall ofthe tube line, as seen from its longitudinal axis, arches toward theoutside. This provides for the possibility of additionally directing thefluid stream, before it enters the rotor-stator dispersion system, insuch a way that any rotation is prevented. In particular, it isenvisioned that the area of the wall where the tube line, as seen fromits longitudinal axis, arches toward the outside opens into the secondopening of the intermediate piece for the connection with therotor-stator dispersion machine.

Depending on what type of fluid must be processed, it may be possible toforego the insertion of the arched section. To be able to respondflexibly to different process requirements, the invention envisions inone advantageous improvement according to the invention that theintermediate piece is configured in multiple parts comprising at leasttwo parts that are detachably connectable with each other. A first partcomprises the pipe in the connection with the first opening. A secondpart comprises the area where the wall of the tube line, as seen fromits longitudinal axis, arches toward the outside.

One improvement of the present invention offers the advantage ofavoiding a rigid constraint of the rotor-stator dispersion machine,thereby also reducing, in particular, the noise development of themachine during operation as well allowing for compensating forexpansions and/or the occurrence of bending moments acting upon therotor-stator dispersion machine, in particular in batches at highertemperature and CIP cleaning and/or sanitizing at high temperatures. Tothis end, the second part of the intermediate piece comprises at leastin the area where the wall of the tube line arches toward the outside,as seen from its longitudinal axis, a flexible element; specifically, itis defined by the flexible element. Used as a flexible element is, forexample, a suitably shaped rubber bellows.

To be able to provide an additional conveying means for rotor-statorsystems with high suction power the invention further envisions that thearea where the wall of the tube line, as seen from its longitudinalaxis, arches toward the outside defines a chamber for receiving such aconveying means for transporting the feed stream of a fluid from thecontainer to the rotor-stator dispersion machine, in particular forreceiving at least one blade of an agitator. In an especially preferredembodied example the chamber for receiving a conveying means is,adjusted to the dimensions of the conveying means, in particularadjusted to the diameter of the agitator blade, dimensioned specificallyin such a way, that during operation the part ΔV=V−V_(RS) of the fluidthat is fed to the rotor-stator dispersion machine by the conveyingmeans V (V_point) that exceeds the conveying power of the rotor-statordispersion machine V_(RS) (V_point_RS) is directed from the pressureside of the conveying means along the arched wall of the chamber to thesuction side of the conveying means.

To provide for a further possibility for disrupting any rotation in thefluid stream that is fed into the rotor-stator dispersion machine theinvention envisions that the intermediate piece comprise a part thatgrips around the tube line immediately before the second opening of theintermediate piece and that contains at least one, preferably three, andespecially preferably four, flow disrupters. These can be configured, inparticular as so-called “Sanitary” flow disrupters. A configuration inwhich the flow disrupters are dimensioned in such a way that they, whenthe intermediate piece is connected with the dispersion machine, extenduntil a point closely above the rotor-stator system, in particularclosely above the rotor, has proved especially favorable. The distancebetween the flow disrupter and the rotor is preferably approximately0.25% to approximately 1% of the diameter of the rotor.

In order to be able to achieve an especially reliably targeted stream ofthe fluid when it flows toward the rotor-stator system the inventionprovides a conveying means for use in the above-described intermediatepiece, and wherein the conveying means comprises an agitator with atleast one agitator blade and a sleeve that envelops the agitator blade.

The sleeve that can also be called a guide sleeve with regard to thefluid that it conveys during operation; it constitutes a jacket aroundthe mixer blade, thereby preventing any radial and outward release offluid, as viewed from the agitator shaft. By preventing the radialrelease of fluid the guide sleeve provides for a higher reflux from thepressure side to the suction side of the agitator. This way, apropeller-type agitator can convey, for example, double or triple thevolume flow that is processed by the rotor-stator system. The propelleris positioned, with the guide sleeve, inside the flexible element insuch a way that the corresponding suction excess is optimallyrecirculated in a direction diagonally upstream in front of the mixerblade. The recirculation of the flow to the suction side of theconveying means occurs at an angle so that drawn-in and recirculatedproduct-parts collide, and whereby the collision decelerates anypossible rotating movement inside the suction channel. This causes asuppression of the rotating movement inside the fluid, thereby avoidingany possible over-concentrations and in-homogeneities inside theproduct. Moreover, the partial recirculation ensures better intermixingof the product before the feed stream reaches the dispersion machine.

After the processing of the fluid in the dispersion machine it oftencontains at least in part size-reduced drops or particles that are notsufficiently stabilized yet and therefore tend to re-coalesce and/orre-aggregate. In order to avoid this from occurring it is advantageousto be able to maintain turbulent flow conditions even after the flowleaves the rotor-stator dispersion machine so as to prevent theparticles from being relatively close to each other in a laminar flow;instead, they are only exposed to relatively brief collisions.Coalescence and/or aggregation are, moreover, promoted in areas wherethe flowing fluid is subject to a dynamic pressure.

Conventional dispersion machines often use a pipe as an outlet channelfrom the rotor-stator dispersion machine. A comparison of the exit areasof the toothed ring of the outer stator with the cross-sectional area ofthe pipe reveals that the cross-sectional area is considerably smaller.The total radial discharge of fluid through the toothed ring of theouter stator must pass through this small opening, which means the fluidmust in part travel long distances and is exposed therein to areashaving different flow rates as well as to zones having low movement withhigh dynamic pressures. An outlet channel of this type, which is in theshape of a relatively thin pipe, can be viewed as a sudden narrowing.

Based on fundamental principles for the definition of turbulent andlaminar flows by Reynolds, which provide that the total resistanceinside a flowing fluid is the sum of the frictional resistance and thepressure drop resistance, the inventor has developed the followingmeasures for minimizing the total resistance.

-   -   The fictional resistance is to be minimized by providing, as        much as possible, a laminar boundary layer. Gradual transitions        are envisioned to this end in the geometric configuration of the        flow-conveying components.    -   The pressure drop resistance in the case of the circum-flow of a        body is to be reduced by providing that the point of        disengagement is shifted as far possible to the rear of the        body.

Both influences overlap.

The transition from laminar to turbulent flow conditions can becharacterized for different types of flows by indicating the Reynoldsnumber Re. According to the model concept by Reynolds, a laminar flowbecomes unstable to disturbances at higher Re numbers such as, forexample, oscillations and vibrations, which are always present in natureand technology. Such small disturbances can influence and in fact causethe switch-over from a laminar to a turbulent flow. Regarding theflow-through of a pipe having a circular cross-section this switch-overoccurs at approximately Re=2300. The more violent these disturbances,the lower the Reynolds number when the laminar flow switches over to aturbulent flow.

The invention therefore envisions that the outlet channel or outletchannels are configured in such a way that a large, gradual, continualtransition be provided from the outer toothed ring in the rotor-statorsystem toward the line that leads away the fluid, for example therecirculation line, in order to minimize dynamic pressures. This goal isachieved by a large-area outlet channel. Vibrations are created at thelarge-area top and bottom sides of the outlet channel, which means atits flat sides, due to the high flow rates that support the turbulentflow.

The invention thus provides an outlet apparatus for connecting arotor-stator dispersion machine comprising a rotor-stator system havingat least one toothed ring, a discharge apparatus, in particular a tubeline, for discharging the fluid from the rotor-stator dispersionmachine, and wherein the outlet apparatus comprises at least one outletchannel having a first opening for the connection with the outsidehousing of the rotor-stator dispersion machine inside an areasurrounding the rotor-stator system and having a second opening for theconnection with the discharge apparatus. The first opening has arectangular cross-section. The second opening has a smallercross-sectional area than the first opening, whereby cone-shapedtapering is achieved over the length of the discharge apparatus betweenthe first and the second openings.

In an advantageous improvement of the invention the length L_(aus) ofthe outlet channel corresponds at least to the largest width of therectangular first opening. This results in an especially long, flatoutlet channel with a gradual transition into the discharge apparatus.To be able to easily connect the outlet apparatus to a pipe theinvention further envisions that the second opening is circular.

In an advantageous improvement of the invention the connection measureof the first opening is adjusted to the area through which the fluidpasses when it leaves the rotor-stator system in order to be able totake over and transport the flow from the rotor-stator system to theoutlet apparatus, essentially without the flow having to pass throughany widening or narrowing. To this end the outlet apparatus isconfigured in such a way that the sum of the cross-sectional areas ofthe first opening of all outlet channels corresponds essentially to thetotal free area between the teeth of the toothed ring that is locatedadjacent to the first opening when the outlet apparatus is connected tothe rotor-stator dispersion machine.

Even if the flow guidance according to the invention is visibly improvedin comparison to the prior art, when using one outlet channel it may attimes still be difficult to ensure a turbulent flow through the entireinstallation with the rotor-stator dispersion machine. Consequently,another considerable improvement is therefore an outlet apparatus withseveral outlet channels. Even with a so-called “dual outlet channel,”which means one outlet apparatus having two outlet channels, it ispossible to maintain the turbulent flow during operation more reliably.A so-called “Quadro outlet channel,” which means an outlet apparatushaving four outlet channels, has proved especially advantageous.Especially the contour of having four outlet channels, which isdescribed in more detail below, helps to keep the dynamic pressuresacting on the walls and transitions relatively low. A Reynolds number ofRe=10.000 can thus be maintained.

An advantageous improvement of the invention provides for an outletapparatus where the transition from the lateral area of one outletchannel to the lateral area of the neighboring outlet channel describesthe shape of an arc. The desired gradual transition of the flow-carryingcomponents from one into the other is further supported if according toanother embodied example of the invention the first opening of each ofthe outlet channels is dimensioned in such a way that each outletchannel essentially transitions directly into the neighboring outsidechannel.

For a flexible utilization of the outlet apparatus that allows forprocessing different material systems and in order to provide for thepossibility, in particular, of so-called “late product differentiation”(LPD) an advantageous improvement according to the invention envisionsthat at least one outlet channel comprises a feed apparatus for addingingredients in solid, powdered and/or liquid form to the fluid, whichflows out of the rotor-stator dispersion machine through the outletchannel during operation.

Using the individual measures as provided in context of the inventionsimplifies the production of stable, fine-particulate dispersions byoptimizing how the flow is directed through an entire installationcomprising a premix container, rotor-stator dispersion machine andcirculation line and/or discharge apparatus for maintaining turbulentflow conditions. The invention provides an inlet pipe connection inorder to evenly recirculate the product from the rotor-stator dispersionmachine to the container and with the fluid inside the container, whiledisrupting the flow conditions as little as possible.

The inlet pipe connection is configured for adding fluid to a container;wherein the container is envisioned for providing the fluid for aprocessing action inside a rotor-stator dispersion machine and has alongitudinal axis and a container wall with a container wall opening.The inlet pipe connection comprises an inlet opening that is to beconnected with the container wall opening and a feed opening that is tobe connected with a feed line. Furthermore, the inlet pipe connectioncomprises a tube line that extends essentially between the feed openingand the inflow opening. The tube line has, at least in some sections, aninclined longitudinal axis with regard to the plumb line relative to thelongitudinal axis of the container, and wherein the incline is at anangle in the range of 0° to 180°, preferably an angle in the range of30° to 150°, and especially preferably at an angle in the range of 90°to 120°.

An advantageous improvement according to the invention provides that thelongitudinal axis of the tube line encloses an angle of α₁₀₀ (alpha_100)with the plumb line relative to the longitudinal axis of the container,and wherein the inlet pipe connection is provided for the connectionwith a container that is at an angle of α_(Konus) along the taperedcontainer floor toward the outlet, which is in contact with thecontainer wall opening. The value of the angle α₁₀₀ therein is α₁₀₀=90°to 90°±½ α_(Konus).

To be able to adjust the desired defined flow conditions it sufficesaccording to the invention to provide an inlet pipe connection having apipe length L_(Ein) that is a value in the range of the twice to sixtimes the diameter of the feed opening.

To allow for an even distribution of the product that is recirculated tothe container during operation and over an area that is as large aspossible a further embodied example according to the invention envisionsthat the area of the tube line that opens into the feed opening has acontour that widens in the direction of the feed opening. It has provedadvantageous in this context if the area of the tube line that opensinto the inlet opening has a contour that widens in the direction of theinlet opening in the shape of a circular arc having a radius R₁, andwherein it is preferred for the radius R₁ to be at least one half of thediameter D₁ of the container.

An installation system for producing dispersions containing at least onefluid comprising a container, a rotor-stator dispersion machine and adischarge apparatus as well as an intermediate piece for the connectionof the rotor-stator dispersion machine with the container and/or anoutlet apparatus for the connection of the rotor-stator dispersionmachine with the discharge apparatus and/or an inlet pipe connection foradding fluid to the container offers an opportunity for utilizing one orseveral of the aspects according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Subsequently, the invention will be illustrated in further detailreferring to the enclosed drawings. Identical components are identifiedby the same reference sign. Shown are in:

FIG. 1 schematic representations 1A, 1B, 1C, 1D and 1E of systemsaccording to the prior art;

FIG. 2 a schematic representation, seen in a cross-section, of anintermediate piece that is connected with a container and a rotor-statordispersion machine according to a first embodied example of theinvention;

FIG. 3 a schematic representation, seen in a cross-section, of a part ofan intermediate piece according to a further embodied example of theinvention;

FIG. 4 a front view, top view and sectional view of a conveying meansaccording to the invention;

FIG. 5 a schematic representation, seen in a cross-section, of anintermediate piece that is connected with the container and arotor-stator dispersion machine according to a further embodied exampleof the invention;

FIG. 6 a photograph of an inside view of the part of an intermediatepiece comprising a flow disrupter according to a further embodiedexample of the invention;

FIG. 7 a schematic representation, seen in a cross-section and partialsectional top view, of a stator for a rotor-stator dispersion machine,specifically for use in combination with an outlet apparatus accordingto the invention;

FIG. 8 a sketch of a rotor-stator system, seen in a cross-section, toillustrate a model concept for the flow;

FIG. 9 a schematic representation, seen from the top with a modelconcept for the flow, of an outlet apparatus that is connected with arotor-stator dispersion machine;

FIG. 10 a front view, rear view, lateral view and top view as well as aperspective view from the front and the rear of a schematicrepresentation of an outlet apparatus according to the invention;

FIG. 11 a schematic representation, seen in a top view, of an outletapparatus with two outlet channels;

FIG. 12 a schematic representation, seen in a top view and a lateralview, of an outlet apparatus with four outlet channels according to afurther embodied example of the invention;

FIG. 13 a schematic representation, seen in a top view and a sectionalview, of an inlet pipe (FIG. 13A);

-   -   a schematic representation, seen in a lateral view, of a        connection of an inlet pipe according to a further embodied        example of the invention (FIG. 13B);    -   a schematic representation, seen in a top view, of an inlet pipe        according to a further embodied example of the invention (FIG.        13C);

FIG. 14 a schematic representation, seen in a lateral view, of aninstallation according to an embodied example of the invention;

FIG. 15 a schematic representation, seen in a longitudinal view and alateral view, of a feed apparatus;

FIG. 16 a diagram that plots the volume flow of the rotor-stator systemas a function of its speed;

FIG. 17 a diagram that plots the torque of the rotor-stator system as afunction of its speed;

FIG. 18 a schematic representation, seen in a longitudinal section, ofan installation configured as a late product differentiation system, aso-called “LPD unit” according to a first embodied example of theinvention;

FIG. 19 a schematic representation, seen in a longitudinal section, ofan installation configured as a late product differentiation system, aso-called “LPD unit” according to a second embodied example of theinvention.

DETAILED DESCRIPTION

System installations as set forth by way of some typical examples inFIG. 1 are often used in the production of dispersions that contain atleast one fluid. The installations comprise a container 1, whichcontains at least one fluid, a dispersion machine 4 and a recirculationline 10 that returns the fluid to container 1 after the fluid wasprocessed inside the dispersion machine 4. The basic configuration of aninstallation is shown in FIG. 1A.

It is possible to use a scraping agitator in order to improve theintermixing of the fluids in container 1 (see FIG. 1B). Furthermore, tosupport the intermixing of the fluid in container 1, it is possible toemploy double-motion agitators, as shown in FIG. 1C. The dispersionmachine 4 is connected at the container floor of container 1 and drawsthe product from container 1 pumping it via the recirculation line 10,which is located outside of the container 1, back into the container.The product can be recirculated into the container, as shown in therespective FIG. 1 above, from above the fluid level.

On the other hand, the product can also be recirculated to the container1 from below the fluid level, as demonstrated by the lines in FIG. 1that extend laterally of the recirculation line 10 into the container 1.The dispersion machine 4, which is mounted below container 1, isconfigured for the production of flowable materials, such as, forexample, emulsions or suspensions. In what follows below these will bedesignated by the terms “dispersion” or “fluid” and in part also“product.”

In the installations that are depicted in the FIGS. 1A to 1C therotor-stator dispersion machine is disposed coaxially relative to thelongitudinal axis of the container 1. FIG. 1D demonstrates a solutionfrom the prior art in which the rotor-stator dispersion machine 4 isdisposed at an angle of inclination of more than 90° to 120° relative tothe longitudinal axis of the container 1. This configuration createsmajor problems due to bending stresses within the dispersion machine.But the rotating movement of the fluid that the fluid brings with itwhen transitioning from the container into the rotor-stator dispersionmachine is only throttled slightly. FIG. 1E shows a rotor-statusdispersion machine that is disposed at an angle of 90° relative to thelongitudinal axis of container 1. But, due to the fact that the fluid isredirected in this configuration, this solution as set forth in thisexample from the prior art suffers from the disadvantage of reducedsuction power by the rotor-stator dispersion machine 4.

However, especially rotor-stator dispersion machines with high suctionpower tend to set the fluid that is drawn from the container 1 into arotating motion, which reduces the dispersion performance. For anemulsion this means, for example, a broader drop-size distribution.Regarding lower fluid levels in container 1, these conditions willresult in the formation of vortices that will in an undesired fashionalso draw air into the product. The intermediate piece 2 according tothe invention serves to prevent this disadvantageous fluid rotationduring the transition from container 1 to the rotor-stator dispersionmachine 4.

FIG. 2 shows an apparatus according to a first embodied exampleaccording to the invention in which an intermediate piece 2 is disposedat the location of the transition of container 1 and the rotor-statordispersion machine 4. The rotor-stator dispersion machine 4 comprises ahousing 40 inside which a rotor 41 and a stator 42 are coaxiallydisposed relative to each other. The rotor 41 is rotably supported on ashaft 115 and can be driven by a motor 116. The container 1 transitionsin the area of the container floor 14 into the outlet 12 of thecontainer. The intermediate piece 2 is connected with the container inthe area 13, which is the container wall that is adjacent to thecontainer wall of floor 14 of outlet 12, as indicated in FIG. 2 by theflange connection.

The intermediate piece 2 has an opening 21 for the connection with theoutlet of the container 1. The intermediate piece has a further opening22 by which the intermediate piece 2 can be connected with therotor-stator dispersion machine 4. During operation fluid is drawn fromthe container 1 through the outlet of container 2 and into the opening21 of the intermediate piece 2. The fluid passes through theintermediate piece 2 through its tube line 25 and enters the dispersionmachine 4 through the opening 22. The fluid travels through the rotor 41and the stator 42 of the dispersion machine 4 and exits the dispersionmachine through an outlet apparatus 5.

Tube line 25 of the intermediate piece 2 has a longitudinal axis 250that is inclined relative to the longitudinal axis 150 of the container1 by the angle α₃₀. The angle α₃₀ can be selected in the range of below90°. It is expedient for the angle α₃₀, to be in the range betweenapproximately between 20° and approximately 60°. In an especiallypreferred embodiment the intermediate piece 2 is provided for theconnection of a dispersion machine 4 with a container 1 having acontainer floor 14 that is tapered toward the outlet 12 at an angle ofα_(Konus). If the angle α₃₀ is one half of the angle α_(Konus), duringoperation, the fluid from container 1 enters the tube line 25 of theintermediate piece 2 directly over the conical floor and is fed at theangle of the intermediate piece into the dispersion machine. Feeding theproduct directly over the tapered floor into the dispersion machine, dueto the installation angle α₃₀ of the intermediate piece 2, results in anespecially efficient suppression of the rotational movement of the fluidinside the container before the fluid enters the dispersion machine 4.

In the preferred embodied example according to the invention that isshown in FIG. 2 the intermediate piece 2 is configured in two partscomprising a first part 210 and a second part 220. The parts 210 and 220can be integral components of the intermediate piece 2 according to theinvention. But in order to achieve better flexibility part 220 is, asshown in FIG. 2, configured as a separate component of the intermediatepiece 2 and can be connected to part 210 by way of a flange connection.The intermediate piece 2 assumes a double function in the preferredembodied example as shown in FIG. 2. On the on hand, the fluid isredirected by the angle α₃₀ before it enters the dispersion machine and,on the other hand, using an agitator 31, the fluid can be acceleratedbefore it enters the dispersion machine 4.

The agitator 31 comprises, for example, a propeller-type agitator blade3 and is connected by its shaft 32 with rotor 41. During operation theagitator 31 can be driven by a motor 116. Using the agitator, the fluid,which is fed from the container 1 and the tube line 25 of theintermediate piece into the dispersion machine 4, is accelerated in thedirection of the dispersion machine. Due to the suppression of therotary motion, which the fluid could bring along with it from thecontainer 1, inside the tube line 25 of the intermediate piece 2, it ispossible to support optimum pumping action of the dispersion machine.

This action according to the invention is improved further by theintermediate piece 2 defining a chamber 26 for receiving the agitatorblade 3, and wherein the chamber 26 is delimited toward the outside bythe arching of the wall of the intermediate piece, as seen from thelongitudinal axis 250 of the latter. If the second part 220 of theintermediate piece 2 is constituted as a flexible element, such as arubber bellows 27, due to this two-part configuration of theintermediate piece 2, it is possible to achieve an especially easy andat the same time robust construction of the intermediate piece 2.

The rubber bellows 27 has a pre-shaped bulged structure (compare FIG. 2)and thereby forms the chamber 26 in which the agitator blade 3 of theagitator 31 can be disposed. The arching in the area of the chamber isdimensioned approximately in such a way that an annular gap isconfigured between the outer delimitation of the agitator blade 3 andthe adjacent interior wall of the rubber bellows 27 having a width of amaximum of approximately one quarter of the diameter of the tube line 25outside of the chamber 26, which means in the area where there is nowall arching.

With this construction, agitator blade 3 is used for feeding a volumestream V_(propeller) (V_punkt_Propeller) from container 1, when theagitator 31 of the rotor-stator dispersion machine 4 is operated. Thedispersion machine 4 has a conveying power of V_(RS) (V_punkt_RS). Thepropeller is configured in such a way that the volume flow V_(propeller)is larger than the conveying power V_(RS). This means a portion of thefluid that is fed in by the agitator of the dispersion machine does notflow though the dispersion machine during operation but is recirculatedfrom the pressure side 34 of the conveying means 3 to the suction side35.

For especially efficient directing of the flow it is advantageous toguide the occurring partial streams, as much as possible in a directedfashion, especially inside the intermediate piece 2. In order to avoid,to this end, the radial outward release of fluid from the agitator blade3 and thereby any remixing of this outwardly released product with fluidthat passes by the dispersion machine 4 and the agitator blade 3 and isnot taken up and therefore recirculated, the agitator blade is equippedwith a sleeve 33. This ensures that fluid, conveyed in the area that isenveloped by the sleeve, is conveyed from the agitator blade to thepressure side and therefore toward the dispersion machine and fed to thedispersion machine as a targeted defined partial stream.

Simultaneously, the sleeve forms the inside wall of the above-describedannular channel in the chamber 26 between the outside wall of thechamber and the agitator blade 3. On the inside toward the longitudinalaxis 250 of the tube line 25 the annular channel is thus delimited bythe sleeve and constitutes a defined area for the fluid that isrecirculated from the pressure side 34 to the suction side 35 of theagitator blade 3. On the suction side 35 the recirculated fluid collideswith the suctioned fluid, whereby the collision of the correspondingproduct streams contributes further to preventing a rotation of thefluid when it exits the container.

FIG. 3 is a representation of the second part 220 of the intermediatepiece 2. A rubber bellows 27 constitutes the wall 23 of the pipe of theintermediate piece in its second part 220. At both of its ends, therubber bellows 27 has a lip that, seen from the longitudinal axis 250 ofthe part 220, is folded to the outside. The lip engages with acorrespondingly configured connection ring; and it is possible toconnect the part 220 thereto, in the way of a flange connection, andwith the first part 210 of the intermediate piece and/or with thehousing 40 of the dispersion machine. In its middle area 260 the rubberbellows has a convex configuration. Correspondingly, the rubber bellows27 has a bulge that defines a chamber 26.

A conveying means 3, in particular an agitator blade, can be disposedinside the chamber 26. FIG. 4 shows a corresponding conveying means. Theagitator 31 comprises a shaft 32. By the shaft 32 it is possible toconnect the agitator 31 with the rotor 41 or the drive shaft 115 of therotor-stator dispersion machine 4 (not shown in FIG. 4). The agitator 31comprises an agitator blade 3 that defines a propeller-type agitator.The agitator blade 3 is connected to a sleeve 33 at its outer ends. Thesleeve 33 thus forms a jacket for the agitator blade 3. During operationthe sleeve acts as a guide sleeve for fluid that is guided from thepressure side of the agitator blade, which is located in FIG. 4 belowthe agitator blade 3, by the outside of the sleeve 33 to the suctionside, which is located in FIG. 4 above the agitator blade 3, as well asthrough the sleeve 33 for the fluid that is to be guided from thesuction side on the pressure side passing the agitator blade.

Due to the especially configured conveying means 3 with a propeller-typeagitator inside a guide sleeve that is placed inside a flexible elementsuch as a rubber bellows, and wherein the rubber bellows has a convexshape, the invention allows for achieving a visible improvement of thesuction conditions relative to the used rotor-stator dispersion system.By suppressing the rotational movement of the fluid inside theintermediate piece 2 it is possible to achieve optimum pumping action.Drawing through the propeller-type agitator with ring sleeve results inachieving radial release of fluid from the agitator blade, on the onehand, and in, on the other hand, improved recirculation of fluid fromthe pressure side to the suction side of the agitator.

Using the propeller-type agitator it is possible to draw a volume flowV_(propeller) that is larger by a factor 2 to 3 than the throughputV_(RS). This results in a recirculation of the excess volume flow ΔV tothe suction side of the propeller. This recirculated volume flow isreturned at an angle in the suction channel that is constituted by thetube line 25 in the intermediate piece 2, whereby a collision isachieved between the drawn and the recirculated product. This collisioncauses a strong deceleration of the rotational movement that isgenerated by the high speed of the propeller. A part of the recirculatedvolume flow is thus returned to the propeller at slight overpressure.This, furthermore, promotes the intermixing of the product, before theproduct reaches the rotor-stator system. In place of a propeller-typeagitator, within the scope of the present invention it is possible touse any other type of agitator blade geometry that the person skilled inthe art may consider especially suitable for use in connection with theproduct to be processed.

According to the invention the recirculation of the excess volume ΔV tothe suction side of the propeller is possible due to the interaction ofthe agitator blade with a sleeve because the radial release from theagitator is prevented, due to the geometry of the flexible element(compare FIG. 3) and the connection angle of the rotor-stator dispersionmachine α₃₀ via the intermediate piece with at least one area of aparallel connection relative to container wall 13 adjacent to the outlet12.

During operation, when the rotor-stator dispersion machine is connectedto the container, the fluid in the area of the tapered container flooris additionally intermixed. This additional intermixing is especiallypronounced if as little as possible or no additional fluid at all isadded to the fluid that is located inside in the cone. As will beexplained below in FIG. 14, these conditions are achieved by a strongthrottling or complete interruption by way of valve 9 of therecirculation of the product that is removed from the dispersion machine4 via the outlet apparatus 5 (compare FIG. 2) in order to be returned tocontainer 1 via the recirculation line 10 (see FIG. 14).

The above explanations describe, among other things, how, assisted bythe invention, it is possible to suppress the rotation of the fluid inthe area of the transition out of container 1. If an intermediate piece2 with a conveying means 3 is used, due to the rotational motion of theagitator, there exists the risk that the fluid is set in a rotationalmotion also in the transitional area from the pressure side of theconveying means 3 toward to the dispersion machine 4, whereby thesuction power of the dispersion machine 4 will be reduced. To avoid thisrisk the invention provides for at least one flow disrupter in theintermediate piece that is disposed before the dispersion chamber of therotor-stator dispersion machine 4. The dispersion chamber is defined bythe rotor 41 and the stator 42 of the dispersion machine 4.

FIG. 5 shows the corresponding apparatus with a flow disrupter 28. Onthe suction side of the rotor-stator dispersion machine, duringoperation, fluid is supplied to the dispersion chamber with the aid ofthe agitator 31 via the tube line 25 of the intermediate piece; theshaft 32 of said agitator is shown in FIG. 4. At least one flowdisrupter 28 is disposed in this area. The flow disrupter 28 comprises alongitudinal element that is arranged along the longitudinal axis 250 ofthe tube line 25, for example a sheet metal. This sheet metal isdisposed in a radial position relative to the longitudinal axis 250inside the tube line 25 and connected to the wall 23 of tube line 25,for example by a screwed connection 280.

Also conceivable as a holding apparatus for the flow disrupter, asidefrom wall 23, is any other stationary, which means non-rotating,component of the dispersion machine 4. For example, the flow disrupter28 can also mesh by its outside thread with an inside thread that isprovided on a flange, which in turn is envisioned for fastening theintermediate piece 2 on the housing of the dispersion machine 4. In theembodied example according to the invention that is depicted in FIG. 5(compare also FIG. 2) this is a third part 230 of the intermediate piece2.

Part 230 is located directly in front of the second opening 22 of theintermediate piece through which, during operation, fluid enters thedispersion machine 4 from the intermediate piece 2. The flow disrupters28, which the person skilled in the art also refers to as baffle plates,are brought in very close proximity to the rotor 42 in order to preventany rotational movement when the product is taken from the tube line 25into the dispersion chamber of the rotor-stator system. During operationstrong turbulence occurs in the fluid between the flow disrupters 28 andthe inner side of the inner toothed ring of the rotor that is directedtoward the longitudinal axis 250, when the inner toothed ring passes bythe flow disrupters. This further improves the intermixing of theproduct. The intermediate piece 2 and specifically the part 230 togetherwith the flow disrupters 28 can be used in combination with the mostvaried rotor tooth geometries.

In the depiction in FIG. 5 three flow disrupters 28 are disposed evenlydistributed around the longitudinal axis 250. FIG. 6 shows a furtherembodied example according to the invention for the intermediate part 2inside a part 230. Four flow disrupters 28 are disposed inside a tubeline 25. During operation, the fluid flows through the part 230; in theembodied example in FIG. 6 the direction of flow is into the plane ofthe present page. Before the fluid enters the dispersion machine 4through opening 22, it passes by the flow disrupters 28. Any possiblerotational movement of the fluid that can be caused by the rotation ofthe agitator 31 (compare FIG. 2) can thus be interrupted by the flowdisrupters 28.

By redirecting the flow of the fluid that leaves the container 1 withthe aid of the intermediate piece 2 and its inclination by the angle α₃₀relative to the longitudinal axis of the container, as well as the useof the flexible element 27 with the bulge for the formation of a chamber26, which can have a conveying means 3 disposed therein, and finally bythe flow disrupter 28 the invention provides means that are capable ofpreventing a rotation of the fluid immediately before the fluid entersthe rotor-stator dispersion machine 4. This has the added advantage thatany formation of electrostatic charges in the product can be avoidedthat may, in particular, have an uncontrollable influence on the actionof the emulsifiers. Such build-up of static charges of the product iscaused by the friction between the product and the housing of thedispersion machine. A rotation of the product causes additional frictionbetween the product and the housing.

To avoid cavitations in the fluid inside the dispersion chamber duringthe operation of the rotor-stator dispersion machine and/or thecoalescence of drops or aggregation of particles of the dispersion thatis conveyed through the dispersion machine it is necessary for the flowrate of the fluid, and thereby also the pressure inside the dispersionchamber to increase through the dispersion chamber after entry andpassage of opening 22 of the intermediate piece 2 until the point ofexit, which means from the inside to the outside. To this end it isadvantageous if a stator 42 is used together with the intermediate piece2, as described above, for the dispersion chamber of the rotor-statordispersion machine 4 in which the flow-transfer area becomes smallerfrom the inside to the outside.

FIG. 7 shows an example of a stator 42 of this type having two toothedrings 431 and 432. The flow transfer area 433 between the teeth of theouter toothed ring 431 is smaller than the flow transfer area 430between the teeth 432 of the inner toothed ring. The outer flow transferarea 433 can be smaller by a factor of between 10 and 30 percent thanthe inner flow transfer area 430, and wherein the exact value depends onthe geometry and the number of teeth of the outer toothed ring of thestator. The reduction of the transfer area can be achieved by twomeasures.

On the one hand, while maintaining an equal number of openings, theopenings can be configured narrower. But the ratio of the width of theopening relative to the depth of the opening, which is approximately1:1, should be maintained in order to avoid any additional increase ofthe pressure loss during the transfer of the fluid through the teeth ofthe outer toothed ring. In comparable machines this ratio rangesapproximately from 1:3 to 1:4. In this context, the depth is measuredradially relative to the longitudinal axis of the stator. On the otherhand, the housing 40 of the rotor-stator dispersion machine can beconfigured correspondingly in the area that is directed toward thedispersion chamber.

To demonstrate FIG. 8 shows a schematic depiction of the dispersionchamber with the rotor 41 as well as the inner and outer toothed rings431, 432 of the stator. The upper part of the area of housing 40 that isdirected toward the dispersion chamber is, viewed from the longitudinalaxis of the rotor, sloped from the inside to the outside in such a waythat the height of the flow transfer openings of the outer toothed ringof the stator is reduced. In the representation as shown in FIG. 8 thisslope is characterized by angle α₈. The advantage of this measure liesin the fact that the product stream during the flow through thedispersion chamber is accelerated both radially as well as axially,which improves the intermixing inside the outlet channel following afterthe dispersion chamber. The fluid reaches this outlet channel by thefirst opening 51 of the outlet channel that is marked in FIG. 8.

After generating very fine particles in the dispersion chamber of therotor-stator system it is important for these particles to bestabilized. Especially for emulsions it has been shown thatstabilization in turbulent flow helps prevent the coalescing of thedroplets. The scope of the invention therefore also provides for anoutlet apparatus that allows for maintaining a turbulent product flowfor the entire area between the outer tooth ring of the stator and theneighboring housing 40 of the dispersion machine, which transitions intothe outlet apparatus. Consequently, the outlet apparatus is configuredin such a way that a large gradual, continual transition is provided forthe fluid after it has passed the outer toothed ring of the stator andtoward the discharge apparatus from the rotor-stator dispersion machine.This way it is possible, in particular, to minimize high dynamicpressures.

This is achieved by a large-area outlet channel. Due to the high flowrate of the fluid during operation, oscillations and vibrations occur atthe large-area upper and lower sides of this outlet channel, which isits flat side, in support of the turbulent flow. The configuration ofthe outlet apparatus according to the invention with the specialgeometry of the outlet channel is based on the knowledge that the fluid,before reaching the outlet apparatus, passed the dispersion chamber inpartial flows with different histories of their passage. These partialflows will subsequently be referred to as partial flows β1, β2, β3 andβ4.

The paths of these partial flows are schematically represented in FIGS.8 and 9. A first partial flow β2 leaves the dispersion chamber of therotor-stator system and is conveyed, starting at the side that isopposite to the outlet channel, toward the opening 51 along theunderside of the rotor 41 to the outlet channel. The partial flow β2 isaccelerated therein by the rotational movement of the rotor 41. Thisadditional acceleration correlates with the fact that the partial flowβ2 must travel the longest distance of all the considered partial flows,which is why partial flow β2 encounters the largest pressure loss.

We must stress the fact that the explanations regarding the partialflows β1 to β4 and their paths toward the outlet channel are a modelconcept; this model has proved an expedient vehicle for explaining thebasic idea for configuring the outlet apparatus according to theinvention. A second partial flow β4 is conveyed directly toward theopening 51 into the outlet channel, after having passed through thedispersion chamber. This partial flow β4 undergoes the lowest pressurelosses because it is not redirected as the other flows. To deal withthis low pressure loss as well as equalize the differences relative tothe three other partial flows it is possible for the area of the teethin the stator, which are traversed by the partial flow β4, to have aflow area that is smaller by approximately 10 to 30 percent, preferably10 to 15 percent than the other teeth.

For reasons of easier visibility, only the two flows β2 and β4, but notthe flows β1 and β3, are shown in FIG. 8. FIG. 9, however, is aschematic depiction of the full inflow into the outlet channel 50 withall four partial flows. The view as shown in FIG. 9 also shows the rotor41 from a perspective as seen from below with regard to therepresentation in FIG. 8. The rotor 41 and along with it the dispersionchamber of the rotor-stator system is surrounded on the outside by ahousing. A ring channel 49 is configured between the rotor 41 and thehousing 40.

The partial flows β1 and β3 leave the dispersion chamber of therotor-stator system laterally, which means relative to the plane of thepaper as shown in FIG. 8 toward the front or the rear. The partial flowsβ1 and β3 are conveyed inside the ring channel 49 toward the outletchannel 50. If the rotor 41 rotates in a counterclockwise direction(compare FIG. 8), it is possible for a part of partial flow β1 to beconveyed below the rotor 2 and mixed with the partial flow β2. But to alarge extent the partial flow β1 is conveyed into the ring channel 49and from there to outlet channel 50. The partial flow β3 is supported bythe rotational movement of the rotor on its way toward the ring channel49 and from there to the outlet channel 50. The four partial flows β1 toβ4 arrive each from different directions when they enter the outletchannel 50, they collide and intensively intermix with each other. Thishelps to maintain the flow of the fluid stream in the turbulent range,even after leaving the dispersion chamber.

The outlet apparatus 5 comprises an outlet channel 50 having a firstopening 51, and during operation the fluid from the dispersion chamberand/or the ring channel 49 enters the outlet channel 50. The outletchannel 50 has a second opening 52 through which, during operation, thefluid leaves the outlet channel 50. The first opening 51 has a largercross-sectional area than the second opening 52. Consequently, theoutlet apparatus is configured as a concentric restrictor. The firstopening 51 is configured as rectangular having its largest width 510parallel relative to the plane in which the rotor 41 rotates. Referencesign 44 designates the flow area of the ring channel at the locationwhere said ring channel transitions into the outlet channel 50.

The partial flow β1 passes through the flow area 44 as provided in themodel. The reference sign 45 designates the flow area through which thepartial flow β2 passes below the rotor according to the model concept.Reference sign 46 designates the flow area of the ring channel at thelocation where said ring channel transitions into the outlet channel 50.According to the model concept, the partial flow β3 passes through theflow area 46. The flow area 47 is the flow area exiting the dispersionchamber where, according to the model concept, the partial flow β4leaves the dispersion chamber. The partial area 47 is, in particular,the surface in the area where the teeth of the stator are configured insuch a way that they have an approximately 10 to 30 percent, preferably10 to 15 percent, smaller flow-through area than the remaining teeth(compare comments above).

All the flow areas 44, 45, 46 and 47 have approximately the same size,except for area 47 which is smaller by at least 5 percent, preferably byat least 10 percent ranging to at the most 30 percent, preferably at themost 15 percent, than the other areas. The sum of the flow areas 44 to47 corresponds approximately to the free flow area in the dischargeapparatus 48 that can be connected to the outlet channel 50. Thestabilization of the product in turbulent flow is completed inside theoutlet channel 50 and the subsequent discharge apparatus 48.

The following harmonization of the flow areas relative to each other hasproved advantageous to this end. Reference is being made to thecross-sectional area of the tube line 25 in the intermediate piece 2.Its flow area is assumed to be 100 percent. Relative to it the flow areathrough the inner toothed ring of the stator 430 is approximately 50 toapproximately 85 percent. The flow area through the outer toothed ringof the stator 433 is approximately 35 to approximately 70 percent. Thesum of all areas 44, 45, 46 and 47 is approximately 35 to approximately65 percent. The flow area of the discharge apparatus 48 is alsoapproximately 35 to approximately 65 percent.

It is crucial that the sum of the areas 44 to 47 correspondsapproximately to the flow area of the discharge apparatus 48. Theabove-referenced conditions of the flow areas within the dispersionchamber contribute to a suppression of the tendency of the formation ofcavitations inside the dispersion chamber. The selected conditions forthe flow areas between the teeth of the outer toothed ring of the statoras well as for the areas 44 to 47 and the discharge apparatus 48 help toavoid an acceleration drop after leaving the dispersion chamber. Thecritical flow quantity is β1.

FIG. 10 is a representation of the outlet apparatus 5 as seen fromdifferent perspectives. On the top left there is a front view of theoutlet apparatus 5 with the second opening of the outlet channel 52pointing toward the observer. In the top right view the substantiallytapered shape of the outlet apparatus 5 can be seen, with part 53 thatis designated as the cone. On the left side in the middle of FIG. 10 theobserver finds a top view of the outlet apparatus 5, as viewed from thevicinity of the first opening 51, by which the outlet apparatus 5 can beconnected with a corresponding opening in the housing 40 on therotor-stator dispersion machine 4; with the rectangular opening of theoutlet apparatus having its largest width 510 at that location.

The rear view of the outlet apparatus 5 on the bottom right side in FIG.10 provides a view into the substantially rectangular opening 51. Saidopening is, in comparison with the circular opening 52, configured as along and relatively narrow slit with rounded ends. The perspective viewsof the outlet apparatus 5 on the right side in the middle of FIG. 10 andon the bottom left side of the same figure illustrate how, due to theconfiguration of the substantially conical shape 53, a gradually windingtransition is achieved between the opening 51 and the opening 52.

FIG. 11 depicts a further embodied example of the outlet apparatus 5. Itcomprises two outlet channels 50 that are located opposite each other inthe shown representation. During operation, the fluid is directed fromboth outlet channels 50 in one or several discharge apparatuses 48. Thearrow in the present representation points to the discharge apparatuses48. The fluid, which leaves the dispersion chamber, is redirected insidethe ring channel 49 between the rotor-stator dispersion and the housing40 system.

The arrows that are drawn in a solid line represent this redirection.The fluid is directed in the direction of both outlet channels 50. Thearrows that are drawn in a perforated line indicate the partial flows bywhich, during operation, the fluid is directed below the rotor towardthe outlet channels 50. The outlet channels have side walls 54 and 55and 56 and 57 respectively. At the transition between a side wall 54 andan outlet channel 50 to the side wall 56 of the neighboring outletchannel 50 there is located a section of the ring channel 49. The ringchannel 49 is thus interrupted by the outlet channels 50.

The outlet apparatus with two outlet channels can be connected with arecirculation line by an inter-positioned T-piece (not shown). Thedischarge apparatuses 48 that are depicted in FIG. 11 are thus combinedinto a single line. Before the entry in the two supply pipes of theT-piece, it is possible to envision valves in each discharge apparatus48 and/or in each outlet channel 50 and/or in the joint discharge lineof the T-piece (compare also below the description regarding FIG. 14)that can be used to adjust the counter-pressures in the two productstreams of the supply pipes of the T-piece, specifically in order toprevent any cavitations.

The function of the dual system as shown in FIG. 11 having an outletapparatus with two outlet channels is based on the model concept asexplained above using FIG. 9. The outlet apparatus with two outletchannels, on the other hand, is an improvement of the former becausethere are fewer redirections of the fluid, after the fluid has left thedispersion chamber, with the two wide outlet channels. This furtherminimizes the formation of dead space and, therefore any partial laminarflow after the dispersion chamber. The outlet apparatus with two outletchannels offers the possibility of accelerating the product that isreleased at a right angle from the dispersion chamber relative to thetwo outlet channels by the rotation of the rotor 41 toward an outletchannel 50.

The flow transfer surfaces in the area of the outer toothed ring of thestator, which is adjacent to the outlet channel 50, are harmonized withthe surfaces in the outlet channel. The configuration is achieved insuch a way that, during operation, the Reynolds number for therespective fluid can be maintained at above 10,000. This alsocounteracts any coalescence of drops of an emulsion while is passesthrough the outlet channels and the transition from the dispersionchamber into the outlet channels.

In a further embodied example according to the invention the outletapparatus 5 comprises four outlet channels 50. This embodied example isdepicted in FIG. 12. The contour of the outlet channels 50 is selectedin such a way that only small bars remains for the transitions betweenthe channels, which means only very minimal dynamic pressures candevelop that will hardly decelerate the turbulent flow. The graduallywinding transitions from the bars to the outlet channels 50 minimize thedynamic pressures in each outlet channel.

The transition from one side area 54 (55) to the side area 57 (56) ofthe respectively adjacent outlet channel 50 takes an arched course. Thearrows in the sectional view at the bottom of FIG. 12 illustrate themodel concept for the flow of the fluid through the outlet apparatus 5when exiting from ring channel 49 and entering the outlet channels 50.If dynamic pressure develops at the bars at the location of thetransition between two neighboring outlet channels 50, the product wouldbe briefly pressed below the rotor, accelerated there and then pressedinto the next outlet channel.

The outlet apparatus with four outlet channels can be connected to arecirculation line by an inter-positioned double T-piece (not shown).The discharge apparatuses 48 that are shown in FIG. 12 are therebycombined into a joint line. Before entry in the four supply pipes of thedouble T-piece, it is possible to provide valves in each dischargeapparatus 48 and/or each outlet channel 50 and/or in the joint dischargeline of the T-piece before (compare also the description for FIG. 14)that will allow for adjusting the counter-pressures in the four productstreams of the supply pipe of the double T-piece, specifically in orderto avoid any cavitations.

Matching the outlet apparatus 5 with four outlet channels 50 that isdepicted in FIG. 12, the stator of the dispersion machine that is usedin combination with the outlet apparatus 5 can be configured in such away that the sections of the stator that are opposite the entry openingsof the outlet channels 50 have an exit area that is dimensioned in sucha way that it matches the entry openings of the outlet channels 50. Forexample, with the assistance of flow simulations, the person skilled inthe art can implement this configuration in such a way that it ispossible to maintain a Reynolds number of Re<10, 0000 during operation.In this context, the sum of the entry areas in the outlet channels 50 issmaller or equals the sum of the exit areas from the stator.

With the measures as described above, which the invention envisions forthe intermediate piece 2 and the outlet apparatus 5, it is ensured thatthe fluid is always maintained in a turbulent flow from the time it isfirst provided in the container, during the processing in therotor-stator dispersion machine and, after processing, during theremoval from the dispersion machine with the aid of the outletapparatus. As shown at the outset, sometimes it is necessary to exposefluids after an initial run through the dispersion machine to anotherrun. The corresponding installations feature a recirculation line forthis purpose that can be connected with the outlet apparatus by way of adischarge apparatus.

This recirculation line returns the product that has left the dispersionmachine via the outlet apparatus once again to the container. Tooptimize flow toward the container as well the invention furtherprovides an inlet pipe connection. The product has a very high flow rateinside the recirculation line, for example in the range of between 2 and4 m/s, and tends to splash upon a non-decelerated entry into thecontainer. The inlet pipe connection helps to gradually reduce the flowrate upon entry of the recirculated product into the container, wherebythe inflowing product gradually incorporates itself via the taperedfloor of the cone with the product that is already present inside thecontainer, especially if the filling level inside the container is belowthe inlet pipe connection. FIG. 13 is a schematic representation of aninlet pipe connection of this kind. On the right side in FIG. 13A thereis a sectional view showing the inlet pipe connection 7 whichtransitions into an opening 16 in the container wall 15.

The inlet pipe connection 7 has an inlet opening 71; the fluid that isrecirculated via the discharge apparatus enters the pipe connection 7through said opening. The inlet opening 71 is configured as athrough-hole having a diameter D₂ in the side wall of the inlet pipeconnection 7 having a longitudinal axis that is the plumb line 180 ofthe longitudinal axis 150 of the container 1. Inlet pipe connection 7has, furthermore, an feed opening 72 by which the inlet pipe connection7 opens in the container wall opening 16. A tube line 75 of the inletpipe connection 7 extends between the inlet opening 71 and the feedopening 72. The tube line 75 of the inlet pipe connection has alongitudinal axis 76 that encloses an angle α₁₁₀ with the plumb line 180on the longitudinal axis of the container.

According to the invention the inlet to the container is constructed insuch a way that the area from the entry pipe, which is thecross-sectional area 710 of the inlet opening 71, corresponds at most to50 percent of the area of the product entry into the container, which isthe cross-sectional area 720 of the feed opening 72. As shown in the topview left of FIG. 13A, the contour of the tube line 75 widens in thearea 751, which opens in the inlet opening 71, toward the container 1 bya radius R₁ toward the outside.

During operation this results in the inflowing product to be distributedover a large area on the container floor. A sudden expansion is thusprevented in the area 751 so that any occurrence of a shock lossaccording to Borda-Carnot is avoided. A shock loss according toBorda-Carnot could cause strong vortices in the area of the fluid insidethe container where the recirculated product enters through the inletpipe connection. The length of this area with vortices would beapproximately ten times the diameter of the feed opening 72. But theproduct is to be added evenly to the fluid still remaining in thecontainer 1. By an advantageous construction according to the inventionthe product is directed against the opposite wall at an angle α₁₁₀ ofapproximately 90° to 150° and is thereby, expanding in the tube line 75,pressed against the container. The speed decreases continually, and theproduct follows the special contour in the area 751 of the feed opening.This does not result in any vortex formations that could disturb the waythe fluid is directed inside the container. To this end, the totallength L_(Ein) of the inlet pipe connection only needs to be twice tosix times the diameter D_(Ein) of the inlet opening 71. The longer thelength of the inlet pipe connection, the more intense the calming of themedium entering the container.

An improvement according to the invention provides for the angle α₁₁₀ tobe in the range between 45° and 180°. If the angle is 180°, the inletpipe connection can, as shown in FIG. 13B, approach the containerhorizontally at the upper arch of the container for the configuration ofan upper inlet into the container. The entry can also be configuredvertically relative to the container so that the product is directeddownward along the container wall and then distributed onto the productlevel located inside the container.

The following table provides an overview of possible ratios for thecross-sectional areas 710, 720 at different nominal diameters DN of thetube line 75 of the intermediate piece 7:

Nominal diameter of 75 710 in mm² 720 in mm² DN 40 (41 × 1.5 mm) 1134120 × 20 = 2400 DN 50 (53 × 1.5 mm) 1963 200 × 20 = 4000 DN 65 (70 × 2.0mm) 3420 250 × 30 = 7500 DN 80 (85 × 2.0 mm) 5150 250 × 40 = 10000 DN100 (104 × 2.0 mm), 7850 320 × 50 = 16000

FIG. 13C depicts another embodied example of the inlet pipe connection7. In addition to the concave configuration of the curvature radius R₁of tube line 75, viewed in reference to the longitudinal axis 76, thearea 751, where the feed opening opens in the container, has areas thatare directed toward the container wall opening 16, where the feedopening has convex contours in reference to the longitudinal axis 76 oftube line 75. At that location the opening has a curvature radius R₃and/or R₂. The radius R₃ and/or R₂ is at least 1.2-times of half of thecontainer diameter D₁ and at most double of half of the containerdiameter D₁.

FIG. 14 depicts an installation system 120 that comprises a container 1.The percentage figures that are entered in the schematic representationof container 1 illustrate different filling levels of the container,starting with 100 percent at the top and ranging down to a filling levelto four percent at which level the corresponding fluid is only locatedon the tapered container floor. During operation, from the container 1,the fluid enters the intermediate piece 2, before it is fed into therotor-stator dispersion machine 4. After processing inside thedispersion chamber, the fluid leaves the rotor-stator dispersion machine4 by the outlet apparatus 5. A discharge apparatus 48 is connected tothe outlet apparatus 5, which is configured as a tube line andconstitutes a recirculation line 10. The product is returned to thecontainer by the recirculation line 10. Marked in the representation inFIG. 14 are two inlet pipe connections 7 and 8 by which the product canbe recirculated to the inside of the container. When the product hasachieved the desired properties, it can be removed from the system 120by a removal apparatus 100. A valve 9 is integrated in the dischargeapparatus 48, in particular a throttle valve, to be able to adjustand/or control and/or regulate the flow inside the recirculation line.

In one embodied example according to the invention the valve 9 can be acomponent of a control unit and can be configured as an adjusting valve,for example as a flap valve with a lock stop. The control unitcomprises, aside from the control valve, a flow meter for monitoring thevolume flow. The dwelling time inside the rotor-stator system, inparticular in the dispersion chamber, can be controllably adjusted byvalve 9. At the same speed, it is therefore possible to vary thedwelling time in the rotor-stator system by the counter-pressure that isto be adjusted by the valve 9. Dwelling time values of between 0.05seconds and 0.5 seconds have been shown as useful. According to theinvention it is also possible to provide a valve and flow meter at thelocations of all outlet channels 50 of the outlet apparatus 5 in orderto be able to control the respective flows.

The dispersion machine is equipped with a frequency converter (notshown) thereby allowing for a selection of the speed of the rotor. Thus,aside from the rotor speed, the volume flow through the system 120and/or the counter-pressure are flexibly adjustable. In particular, itis possible to adjust different parameters for speed, flow andcounter-pressure depending on whether the system is used for processinga dispersion, on the one hand, of for a cleaning of the system, on theother hand, for example CIP cleaning; this way, the respective processescan be implemented as optimally as possible.

After passing through valve 9 the fluid enters the recirculation line10. By the recirculation line the fluid can be removed via removallocation 100 or recirculated into the dispersion machine. Systeminstallation 120 is designed in such a way that it is possible to adddifferent further ingredients in solid and/or liquid form to the productduring different stages. Examples for such ingredients include, amongothers, active substances or carrier substances such as liposomes, whichcan be added to the fluid in a finely dispersed manner. The system 120comprises several feed apparatuses for this purpose. For example, aninjector 64 is provided that is positioned in the discharge apparatusafter the outlet apparatus 5. With the injector it is possible to add,in particular, powder-type ingredients to the fluid. Further feedapparatuses 60, 61, 62 and 63, 66 allow for adding ingredients in therecirculation line and/or discharge apparatus, in the dispersionchamber, in particular into the ring channel 49, and in the pipe of theintermediate piece 2. A suitable injector can also be a nozzle, such asfor example a tubular or sheet nozzle, as described in the utility modelby the applicant DE 20 2006 001 952 “Device for producing dispersions.”It is possible to incorporate additional valves even before the removal100 and in the recirculation line or in the line that leads to the feedapparatus 66 in the dispersion machine 4.

Incorporating further ingredients into the discharge apparatus 48 via aninjector, which follows the outlet apparatus 5, occurs at slight vacuumpressures inside the container, which means at a pressure that isapproximately 0.3 bars lower than the ambient pressure. At higherspeeds, meaning flow speeds of approximately 3 to 4 m/s, the injectorgenerates a vacuum that is sufficient for drawing liquids without anyfurther applied vacuum into the fluid. The added ingredients areincorporated immediately by the injector jet.

A further improvement for maintaining a turbulent flow during the flowthrough the system 120 can be achieved by attaching at least onevibrator (not shown) to the housing 40 of the rotor-stator dispersionmachine 4 and/or the outlet apparatus 5. In order to avoid that thevibrations associated with the component that is connected to thevibrator are not transmitted to the entire system 120 the recirculationline is provided with flexible elements 105.1, for example sections madeof a sufficiently bendable material.

FIG. 15 shows an embodied example for a feed apparatus 60. The feedapparatus 60 can be connected by a connecting element 650, for example aflange, with the outlet apparatus 5. Using a connecting element 648 itis possible to connect the feed apparatus 60 with the dischargeapparatus 48, in particular the pipe of the recirculation pipe 10. Forthe addition of further ingredients that are to be added to the fluidupon the fluid leaving the rotor-stator-dispersion machine the feedapparatus 60 comprises feed channels 60.1 and 60.2. Depending on thenumber of respective ingredients, it is also possible to envision evenmore feed channels.

On the inside the feed apparatus 60 is configured essentially as a pipehaving a wall contour in the shape of a double cone. Viewed in thedirection of flow (in FIG. 15 from left to right), the diameter firstnarrows by a cone angle of 150° to the narrowest location in order tothen expand again by a cone angle of 58.6°. This creates a shockdiffuser according to Carnot generating such flow conditions duringoperation that it is possible to accommodate the addition of evenpowdered ingredients via the feed openings 60.1, 60.2, as well as theirquick homogeneous distribution in the fluid that flows in the feedapparatus 60. The indicated cone angles are examples that have beenshown to be advantageous. The person skilled in the art will adjust saidangles depending on the type of fluid for which the feed apparatus 60 isto be used.

In order to maintain these flow condition for as long as possible forthe fluid that flows out of the feed apparatus and is transportedfurther into discharge apparatus 48 and/or in order to provide for agradual flow transition to the discharge apparatus, the exit opening ofthe feed apparatus 60 is configured as rounded with a radius R₅.

The diagram in FIG. 16 plots the volume flow in liters/minute over thespeed in revolutions/minute of the rotor-stator dispersion machine fortwo different diameters di32 mm and DN50. To this end, on the one hand,a feed apparatus (see FIG. 15) was installed with an entry DN50 and areduction to 32 mm. On the other hand, a recirculation line having DN50without feed apparatus was used. The employed rotor-stator dispersionmachine had a nominal power of 22 kW and was operated with theintermediate piece according to the invention. Parallel to the increasein speed, the volume flow continually increases.

FIG. 16 shows a torque curve that was recorded with a container having acapacity of 500 liters and a filling level inside the container of 50liters. The used rotor-stator dispersion machine had a nominal power of22 kW and was operated with an intermediate piece according to theinvention. Recirculation of the product into the container occurredusing an inlet pipe connection 7. The torque curve clearly shows thecontinual increase of the torque, which is indicated in % relative tothe maximum torque that can be achieved at maximum speed of therotor-stator system. Moreover, the respectively taken up current(“Amp”), indicated in ampere, increases continually with the increasingspeed of the rotor-stator system.

The continual increase of the volume flow and torque with the increasingspeed of the rotor-stator dispersion machine demonstrates that it ispossible to prohibit, due to the intermediate piece, any influence therotation of the container content relative to the conveying power or therotor-status machine during operation even at low filling levels as lowas 10% of the container.

The invention thus provides for the possibility of using a relativelylarge batch preparation container 1 also for processing smaller batchvolumes of between 3% and 10% of the maximum container filling level.With conventional systems nine different containers are needed to coverall the usual ranges; with the invention, four containers are enough.One container with a system that utilizes the intermediate pieceaccording to the invention is able to cover an area between 40 and 500liters; wherein conventional solutions require respectively onecontainer for 40 to 100 liters, 100 to 250 liters, 200 to 500 liters and350 to 1,000 liters. One further container according to the inventioncan cover the range between 150 to 2,000 liters; wherein conventionalsolutions require respectively one container for 700 to 2,000 liters and1,500 to 4,000 liters. One further container according to the inventioncan cover the range between 500 and 6,000 liters; wherein conventionalsolutions require respectively one container for 2,000 to 6,000 litersand 4,000 to 12,000 liters. Finally, one further container according tothe invention can cover the range between 15,000 and 20,000 liters;wherein conventional solution require one container for 7,000 to 20,000liters.

Example 1 Hair Dye

4 kg Texapon are dispersed in 20 kg water for preparing a batch of 100kg in a system installation comprising a container of 500 kg capacity.For the system with an intermediate piece according to the inventionthis is not a problem because the rotation of the product upon enteringthe dispersion machine is suppressed, due to the connection angle of thedispersion machine with the container and due to the propeller acting inconcert with the flexible element, such as the rubber bellows.

Example 2 Cleaning

The invention allows for reducing water consumption during CIP or SCIPcleaning applications to a minimum to possible minimum water quantities(filling quantity of the container) of 4-5% of the batch size. A systemas described in Example 1 can be cleaned completely with 40 liters totalquantity in two cleaning runs.

Example 3 Producing Anti-Aging Creams Containing Liposomes

In order to incorporate nano-particles, such as for example liposomes,into cosmetics, it is possible to install a tubular or sheet nozzle atdifferent positions between the suction channel and the outlet channel(see reference signs 63, 64, 65). The task of the tubular or sheetnozzle consists in generating minimally-sized particles at highpressures and in spraying them into the fluid flow that must traversethe rotor-stator dispersion machine. The tubular or sheet nozzle isoperated as a nozzle of a high-pressure homogenizer and can beconfigured, in particular, as described in the above cited Germanutility model by the applicant. The position 63 is especially wellsuited because the propeller, with guide sleeve as a conveying meansinside intermediate piece 2, achieves good mixing. But the tubular orsheet nozzle can also be installed in one or several of the furtherconnections 66.

According to further embodied examples it is also possible to use theinvention in the context of systems that operate according to theprinciple of late product differentiation. The late productdifferentiation process is generally as follows: Large batches of a baseproduct are produced; added to this can be depending on the dailyproduction requirements the still-missing ingredients, such as colors,flavors, aromas and/or other additives that can be added, in particulardivided in partial quantities, to round off the product. This means thatlarge batch sizes are finished in several smaller partial quantities ashort time before the product is filled in containers.

This process increases the effectiveness and the flexibility of theproduction process. Due to the fact that it is normally required thatthe system is cleaned between individual steps in the production of thedifferent partial quantities, it is crucial that the LPD unit accordingto the invention is very compact in order to reduce product lossesduring this cleaning step as much as possible. Furthermore, the LPD unitaccording to the invention is easy to clean, for example by CIP(Cleaning in place) and/or automated cleaning and sanitizing (SCIP). Theutilization of the LPD unit according to the invention produces,moreover, extremely small amounts of waste water in comparison toconventional systems.

Example 4A LPD (Late Product Differentiation)

A tubular or sheet nozzle is combined at the feed apparatus 61 with thesystem having the rotor-stator system 4. Large batches have theadvantage of reducing the amount of required manual work and that theindividual steps only have to be implemented once and not several times.This is also true for work in the laboratory. Consequently, in theproduction of hair dye, the coloring agent is expediently incorporatedlast at the very end of the production of the entire batch. For example,a batch of 20,000 kg base product is prepared, and the coloring agent ofapproximately 10 kg is initially not incorporated with the base product.A suitable installation system comprises an outlet apparatus having twooutlet channels and a power rating of 45 kW. A volume flow ofapproximately 3,000 l/min is recirculated inside the system withoutbeing throttled. The recirculation time of the batch is approximately 7minutes. The coloring agent is dosed approximately during a singlerecirculation period; this will result in a very homogenous product.

If the goal is to separate the batch in order to produce two or severalcolorings, the product is colored after its removal 100, and wherein therecirculation line is closed. A small quantity containing a blend of thefirst and second colors is disposed of between the incorporation of thefirst and second colors. Instead of a feed apparatus 61, 62, 63, forexample in the form of a nozzle, it is possible to install two ormultiple nozzles in the nozzle areas.

Example 4B LPD (Late Product Differentiation)

A further possibility provides that the completed batch is drawn off asa partial quantity via the outlet 100, and the excess is recirculated inthe dispersion chamber, and therein the coloring agent or otheradditives are added through a nozzle (preferably 61, 62) in order toachieve more intense intermixing (multiple runs through the rotor-statordispersion machine). The recirculation into the dispersion chamber canbe effected, in particular, by one or several premixing chambers of therotor-stator system, provided a rotor-stator system is used, asdescribed in the German patent application DE 10 2008 022 355.7.

The recirculation line is shut off by a valve behind outlet line 100. Itis expedient to start with the lighter colors that are subsequently moreeasily covered by the darker color. Advantageously, it is thus useful toproduce a base batch of the product (bulk batch) which is completed whenit is pumped from the container by the addition of the still pendingadditives.

Example 4C LPD (Late Product Differentiation) in Special LPD Unit

An LPD unit is a compact system unit for “late product differentiation.”This means in the context of the production of a product, which may bean emulsion, dispersion, suspension, blend or something similar, thefinal ingredients are only dispersed to a prefabricated base product,which can be a concentrate, a short time before the final product isfilled in bottles, tubes, pots or other packing drums. Two exemplarysolutions will be described below that are designated as “LPD unit I”and “LPD unit II.”

For the LPD unit it is possible to advantageously use components incombination that are in part the subject of further patent applicationsand utility models by the applicant. These are specifically thefollowing components:

-   -   a) One or several premixing chambers as described in the patent        application family DE 10 2008 022 355.7-23.    -   b) Rotor geometry as described in the patent application family        DE 10 2008 045 820.1,    -   c) One or several flow disrupters (see above),    -   d) Outlet apparatus, specifically in single and dual        configuration (see above)    -   e) At least one tubular or sheet nozzle according to utility        model DE 20 2006 001 952.

A mixer head is placed on the respective dispersion apparatus comprisingfeed and discharge apparatuses. In particular, the mixer head can beconfigured in such a way that the mixing chamber inside it is configuredsubstantially in the shape of a hollow sphere. In the following such amixer head will be designated a “spherical mixer head.”

The functional operation of the LPD unit will be described below usingthe FIGS. 18 and 19. The product that is to be processed is added to thespherical mixing chamber 300, for example by a flow counter (not shown,)through the product inlet 8, for example by an automated valve. In theshown example the spherical mixing chamber 300 is constituted, on theone hand, by an essentially semi-spherically shaped upper lid thatcomprises connections for the product inlet 8, a blow-off valve 400 (seebelow) and the recirculation line 10, and, on the other hand, by an LPDhousing 200 that is also essentially semi-spherically shaped on itsinside and opens into a pipe in which a propeller 3 and flow disrupter28 are positioned; and said pipe transports the product to thedispersion chamber of rotor 41 and stator 42 and/or premixing chambers220.

The operating dispersion machine 41, 42 draws in the product, and a partof the product is brought in contact with the missing ingredients in thepremixing chamber 220. These missing ingredients are, in particular,added to the premixing chambers 220 by feed apparatuses 250 via flowcounters (not shown) and pumps (not shown). The embodied examples thatare depicted in FIGS. 18 and 19 are each provided with two premixingchambers. But the invention allows for adjusting the number of premixingchambers of the LPD unit depending on the requirements, whereby at leastone but also more than two mixing chambers are envisioned.

The individual components of the dispersion pass through the dispersionchamber, during which process they are dispersed, and the dispersion isrecirculated by the product recirculation line 10 to the mixing chamber300. The product recirculation line 10 is brought back to the mixingchamber 300 in such a way that it counteracts the rotational movement ofthe propeller 3.

Normally the mixing chamber 300 has the approximate diameter of therotor 41 in order to minimize the recirculation volume. For example, byway of a modular design principle, the following rotor sizes can beprovided for the rotor: 25 mm, 50 mm, 100 mm, 150 mm, 175 mm and 285 mm.A blow-off valve 400 is mounted at the highest point of the mixingchamber 300 in order to press residual quantities from the LPD unit to afilling machine downstream of the LPD unit in order to minimize losses.

In addition, in the shown embodied examples a tubular or sheet nozzle600 according to DE 20 2006 001 952 is connected by a flange connectionwith the product circulation line 10 or mixing chamber 300. Depending onthe requirements, it is also possible to forego this additional nozzle600. Using the tubular or sheet nozzle 600 it is possible to achieve anespecially fine dispersion; in particular, with an additional tubular orsheet nozzle 600 it is possible to generate emulsions and/or dispersionsseparately. Correspondingly, in addition to the processes in thepremixing and the dispersion chambers, with the rotor 41 acting inconjunction with the stator 42 inside the latter, it is advantageouslypossible to generate a further emulsion inside the emulsion.

At the same time, when the (not shown) valve is opened at the productinlet 8, the (not shown) valve at the product outlet 648 is also atleast slightly opened in order for the inflowing product and theoutflowing product to be substantially balanced and the overpressurethat is generated to only slight. The valve at the product outlet 648can be configured, in particular, in such a way that it is only opens inits lower area (semi-ball-type valve) so that only the product that isreleased below the rotor is discharged through the product outlet 648.

After the outlet channel 50 follows, aside from the product outlet 648and the recirculation line 10, also a pipe connection for the rinsingwater outlet 500.

It is also possible to use outlet channels according to theabove-described “dual” embodied example, and wherein one outlet channelleads, for the purpose of recirculation, to the recirculation line 10and a further outlet channel for the discharge of the product from themachine to the (not shown) filling machine that is disposed downstreamof the LPD unit.

The dispersion machine internally recirculates approximately a productquantity that is ten times the quantity that is added and/or discharged.The result is a homogenous mixing of all ingredients before the productleaves the LPD unit.

The propeller 3 is mounted and positioned inside the LPD unit in such away that at least one third of the drawn-in product is pressed radiallyover the floor of the mixing chamber 300. This process optimizes theinternal premixing inside the mixing chamber with the assistance of thegentle propeller mixing.

Normally the goal is to produce a homogenous product with the fewestnumber of runs through the LPD unit as possible. This is achieved withthe described mixing chamber 300 of the LPD unit, due to the optimizedpremixing of the base product with the recirculated product inside themixing chamber 300.

For example, using a base product as foundation it is possible toproduce a face cream in the following manner.

Approximately 1 vol-% liquid coloring agent and 0.1 vol.-% aroma agentsare added in the LPD unit to the base product. A filling machinedownstream of the LPD unit having a capacity of 200 tubes per minute,tube size 60 ml, requires approximately 12 kg product/minute. Arecirculation ratio of 1:5 is adjusted for the correspondingly viscousproduct; this means one volume part is removed while five volume partsare recirculated.

This production method can be implemented, for example, using a productby the applicant designated as “LPD-Unit LM 100” having a rotor diameterof 100 mm. The total volume of the LPD unit is below two liters, andwherein (measured with water) a recirculation volume of approximately8,000 liters/hours is achieved at 23 m/sec.

FIG. 19 shows a further embodied example of an LPD unit. In contrast tothe embodied example that is seen in FIG. 18, the outlet channel 5 isseparated from the recirculation line 10. The premixing chamber 220 thatis shown on the left side in FIG. 18 is drawn as offset and located nextto the premixing chamber 220 in FIG. 18 on the right side, in the areaof the internal product recirculation. The product stream divides intoan internal product recirculation and a product outflow in the directionof the product outlet 648. This means that the discharged product doesnot come into contact with a premixing chamber 220 when it leaves theLPD unit.

Example 5 Silicone Dispersion

Rotor-stator systems are suitable for the production of industrialdispersions of 5 weight-% silicone in 95 weight-% water (quantitiesincluding emulsifiers) with the smallest droplet sizes in the range ofseveral nanometers. Rotor-stator systems demonstrate very good dropletbreakdown at higher viscosities. Consequently, 5% silicone is preparedin the container, dispersed into this are approximately 2 to 3% waterusing a suitable emulsifier, the mixture is intensively homogenizedand/or dispersed and then mixed with the remaining water.

Example 6 Emulsion with Phase Inversion O/W

The goal is to produce an emulsion with an inner phase of 4weight-percent. The oil and wax phases are prepared in the container. Anapproximately 4% part of the water phase is added and dispersed withinthe mixture so that a water-in-oil emulsion results. The water phase canbe added cold; the result is a mixed temperature that can be above thesolidification point of the oils and/or waxes. After the finisheddispersion, the remaining quantity of water is added and the phaseinversion occurs. If necessary, it is possible to add further rawmaterials. Cooling of the batch is not necessary because the water phasewas added cold. This saves considerable amounts of energy andbatch-preparation time.

Example 7 Scale Up

Laboratory and production machines should for the most part have thesame geometries and operational parameters; moreover, they should allowfor conducting the involved processes in the same time-related manner.With the product flow, optimized by the invention, through therotor-stator dispersion machine and/or system installation it ispossible to produce the smallest laboratory dispersion machines havingbatch volumes of between 0.1 and 1.0 liters for the preparation ofcomparable products as with production machines.

The smaller the dispersion machine, the larger becomes the ratio of thesurface relative to the operational volume of a dispersion machine. Thisresults in higher losses due to friction and/or pressure losses in thedispersion machines of decreasing size. This negative influence isespecially great when processing products having high viscosity as, forexample, the products listed in the above examples. Due to the adhesionof the product on the surfaces, flows are interrupted. Using thefollowing geometric diameter ratios, a scale-up according to theinvention has proved very much possible: for a laboratory machine havinga capacity of one liter the ratio of the diameter of the rotor-statorsystem relative to the diameter of the container is 120 mm/24 mm=5. Fora production machine having a capacity of 500 liters the ratio of thediameter of the rotor-stator system relative to the diameter of thecontainer is 930 mm/150 mm=6. The ratio of 5/6 is to be viewed assufficiently similar.

Example 8 Preparation of Emulsions

Oil-in-water emulsions of mineral oil and water were produced. Tween 80and Span 20 were used as emulsifiers. The total duration of theproduction was 15 minutes.

A two-tank system was employed for preparing the fluids. 24 liters of anaqueous emulsifier solution were prepared in a container having a volumeof 30 liters. 6 liters oil was provided in a further preparation tank.The container is connected by a line with a transfer pump with thepreparation tank. A rotor-stator dispersion machine is connected to thetwo-tank system. Advantageously, it is possible to use a rotor-statordispersion machine with a premixing chamber according to the Germanpatent application DE 10 2008 022 355.7 by the applicant for adding theoil phase.

The dispersion chamber with the rotor has a diameter of 100 mm. At arotor speed of 1,000 revolutions per minute the peripheral speed is 5.2m/s. At a rotor speed of 5,000 revolutions per minute the peripheralspeed is 26 m/s. After passing through the rotor-stator dispersionmachine the emulsion was recirculated to the container by an outletapparatus with an outlet channel.

For the tests listed in the table below with numbers 1 to 6 the oil wasadded slowly at six liters per minute.

Experiments were conducted with a fully opened valve 9 (compare FIG.14); they are marked by “Open” in the table below. Moreover, experimentswere conducted in which the valve 9 was two thirds closed, therebygenerating an artificial dynamic pressure. These experiments are markedby “Dynamic Pressure” in the table below.

In the column “Test 1 (μm)” the results are indicated for the mean dropsize of an emulsion after a one-time run through the dispersion machine.In the column “Test 2 (μm)” the results are indicated for the mean dropsize of an emulsion after multiple runs through the dispersion machinein the circulation after a total duration of the experiment of 15minutes.

The drop size distributions were determined with a measuring instrumentby the equipment manufacturer Horiba in accordance to the principle oflaser light refraction. “Average Size” refers to the mean value from theresults from Test 1 and Test 2.

Test 1 Test 2 Rotor speed (rpm) 3,000 3,000 Valve 9 Open Dynamicpressure Test 1 (μm) 0.812 1.91 Test 2 (μm) 0.804 2.04 Average size (μm)0.808 1.975 Test 3 Test 4 Rotor speed (rpm) 4,000 4,000 Valve 9 OpenDynamic pressure Test 1 (μm) 0.437 1.340 Test 2 (μm) 0.440 1.330 Averagesize (μm) 0.439 1.335 Test 5 Test 6 Rotor speed (rpm) 5,000 5,000 Valve9 Open Dynamic pressure Test 1 (μm) 0.374 0.608 Test 2 (μm) 0.371 0.610Average size (μm) 0.373 0.609

A further experimental series involving Tests 7 to 12 was conducted withthe quick addition of the oil; i.e., six liters over the course of 20seconds. The results are shown in the table below.

Test 7 Test 8 Rotor speed (rpm) 3,000 3,000 Valve 9 Open Dynamicpressure Test 1 (μm) 0.561 2.370 Test 2 (μm) 0.562 2.290 Average size(μm) 0.562 2.330 Test 9 Test 10 Rotor speed (rpm) 4,000 4,000 Valve 9Open Dynamic pressure Test 1 (μm) 0.405 1.710 Test 2 (μm) 0.406 1.720Average size (μm) 0.406 1.715 Test 11 Test 12 Rotor speed (rpm) 5,0005,000 Valve 9 Open Dynamic pressure Test 1 (μm) 0.351 0.460 Test 2 (μm)0.353 0.441 Average size (μm) 0.352 0.451

A raw emulsion (premix) was produced in the container in a furtherexperiment with completely opened valve 9; specifically by premixing theoil phase and the water phase. The raw emulsion had a drop sizedistribution of a mean diameter of approximately 37 micrometers.

After passing through the rotor-stator system at a speed of 4,000revolutions per minute, the mean diameter was only 5.363 micrometers. Ifthe raw emulsion is directed through the rotor-stator system once moreat 5,000 revolutions per minute, the achieved mean diameter is 2,504micrometers. If the product is run for 15 minutes inside the circulationthrough the system at a rotor speed of 5,000 revolutions per minute, itruns approximately 52 times through the dispersion machine; the achieveddrop diameter is 0.347 micrometers. The above figures relate to onemeasurement. As in tests 1 to 12, several measurements were conducted aswell. The results are summarized in the table below.

Raw 1 passage, emulsion 4,000 rpm Test 1 (μm) 36.097 5.363 Test 2 (μm)37.775 5.471 Average size (μm) 36.936 5.417 15 minutes 1 passage, at5,000 rpm 5,000 rpm Test 1 (μm) 2.504 0.347 Test 2 (μm) 2.548 0.342Average size (μm) 2.526 0.345

The experiments as described above for the production of an emulsionclearly show the influence of the counter-pressure and/or dynamicpressure relative to the droplet size, which can be applied by thepositioning of the valve 9. Furthermore, the experiments show that theinvention makes it possible to achieve the smallest size droplets. Thesedroplets are smaller than the smallest mean drop sizes that can beachieved with conventional rotor-stator systems. This demonstrates theadvantageous effect of the invention which helps to create and maintaina turbulent flow throughout the entire installation system.

It is clear to a person skilled in the art that the scope of theinvention is not limited to the previously described embodied examplesbut that it can be varied in multiple different ways. In particular, thecharacteristics of the individual embodied examples can be combined orexchanged with each other.

LIST OF REFERENCE SIGNS

-   1 Container (preparation container)-   13 Area of the container wall that is adjacent to the outlet-   150 Longitudinal axis of the container-   180 Plumb line relative to the longitudinal axis of the container-   D₁ Diameter of the container-   12 Outlet of the container-   14 Container floor-   15 Container wall-   16 Container wall opening-   2 Intermediate piece (suction head)-   21 First opening of the intermediate piece-   22 Second opening of the intermediate piece-   25 Tube line of the intermediate piece-   250 Longitudinal axis of the tube line of the intermediate piece-   α₃₀ Inclination angle of the longitudinal axis of the tube line of    the intermediate piece relative to the longitudinal axis of the    container-   23 Wall of the pipe-   260 Area of the tube line of the intermediate piece where the wall    arches toward the outside-   210 First part of the tube line of the intermediate piece-   220 Second part of the tube line of the intermediate piece-   230 Third part of the tube line of the intermediate piece-   26 Chamber for receiving the conveying means-   27 Flexible element, rubber bellows-   28 Flow disrupter-   280 Screwed connection-   3 Conveying means, specifically agitator blade-   31 Agitator-   32 Shaft of the agitator-   33 Sleeve-   34 Pressure side of the conveying means-   35 Suction side of the conveying means-   4 Rotor-stator dispersion machine-   40 Housing-   41 Rotor-   42 Stator-   431, 432 Inner and outer toothed ring of the stator-   430, 433 Transfer area between the teeth of the inner and outer    toothed ring-   44, 45, 46, 47 Transfer areas through which fluid exits the    rotor-stator dispersion machine-   48 Discharge apparatus, specifically tube line-   49 Ring channel-   5 Outlet apparatus-   50 Outlet channel-   51 First opening of the outlet channel-   510 Largest width of the rectangular first opening of the outlet    channel-   52 Second opening of the outlet channel-   53 Cone of the outlet channel-   L_(aus) Length of the outlet channel-   54, 55, 56, 57 Lateral surfaces of the outlet channels-   60, 61, 62, 63, 64, 65, 66 Feed apparatus for adding ingredients to    the outlet channel, injector-   60.1, 60.2 Feed channel-   650 Connecting element (flange) for connecting the feed apparatus to    the outlet apparatus-   648 Connecting element (flange) for connecting the feed apparatus to    the discharge apparatus-   7, 8 Inlet pipe connection-   71 Inlet opening-   710 Cross-sectional area of the inlet opening-   72 Feed opening-   720 Cross-sectional area of the feed opening-   75 Tube line of the inlet pipe connection-   751 Area of the pipe that opens into the inlet opening-   α₁₀₀ Inclination angle of the longitudinal axis of the pipe of the    inlet pipe connection relative to the plumb line of the longitudinal    axis of the container-   76 Longitudinal axis of the inlet pipe connection-   9 Valve-   10 Circulation line-   100 Removal-   115 Shaft-   116 Motor-   117 Seal, mechanical seal-   120 Installation system-   105.1 Flexible element, section of sufficiently bendable material-   200 LPD housing-   220 Premixing chamber-   250 Feed, inlet into the premixing chamber-   300 Spherical mixing chamber-   400 Blow-off valve-   500 Rinse water drain-   600 Tubular or sheet nozzle

What is claimed is: 1-10. (canceled)
 11. An outlet apparatus (5) forconnecting a rotor-stator dispersion machine (4) comprising arotor-stator system (41, 42) having at least one toothed ring (43) witha discharge apparatus (48) for discharging fluid from the rotor-statordispersion machine (4), the outlet apparatus (5) comprising: at leastone outlet channel (50) with a first opening (51) for the connectionwith the outside housing of the rotor-stator dispersion machine in anarea surrounding the rotor-stator system and with a second opening (52)for the connection with the discharge apparatus (48), wherein the firstopening (51) has a rectangular cross-section and the second opening (52)has a smaller cross-sectional area than the first opening so that thelength of the outlet apparatus (5) is substantially tapered as a cone(53) between the first and the second openings.
 12. The outlet apparatus(5) as claimed in claim 11, wherein length L_(aus) of the outlet channel(50) corresponds at least to the largest width (510) of the rectangularfirst opening (51).
 13. The outlet apparatus (5) as claimed claim 11,wherein the second opening (52) is circular.
 14. The outlet apparatus(5) as claimed in claim 11, wherein a sum of the cross-sectional areasof the first opening (51) of all outlet channels (50) substantiallycorresponds to the total free area between teeth of a toothed ring (43)that is adjacent to the first opening (51) when the outlet apparatus (5)is connected with the rotor-stator dispersion machine (4).
 15. Theoutlet apparatus (5) as claimed in claim 11, wherein the outletapparatus comprises at least two outlet channels (50).
 16. The outletapparatus (5) as claimed in claim 15, wherein a transition from alateral area (54, 55) of a first outlet channel to a lateral area (56,57) of an adjacent outlet channel (50) describes the shape of an arch.17. The outlet apparatus (5) as claimed in claim 11, wherein the firstopening (51) of each outlet channel is dimensioned such that,substantially, each outlet channel directly transitions into therespectively adjacent outside channel.
 18. The outlet apparatus (5) asclaimed in claim 11, wherein at least one outlet channel (50) comprisesa feed apparatus (60) for adding ingredients in solid, powder and/orliquid form to a fluid that flows, during operation, through the outletchannel (50) out of the rotor-stator dispersion machine (4).
 19. Theoutlet apparatus (5) as claimed in claim 15, wherein the outletapparatus comprises exactly four outlet channels (50). 20-24. (canceled)25. A system installation (120) for the production of dispersionscontaining at least one fluid, the system installation comprising: acontainer (1); a rotor-stator dispersion machine (4); a dischargeapparatus (48); and the outlet apparatus (5) as claimed in claim 11.